1. Field of the Invention
The present invention relates to an image display apparatus, an image display method, and a recording medium having an image display program stored therein for projecting images. In particular, the present invention relates to an image display apparatus, an image display method, and a recording medium having an image display program stored therein for projecting images by laser light.
2. Description of the Background Art
Projectors are now used in a variety of scenes to project images on projection surfaces such as screens or walls. In recent years, a wide variety of projectors have been developed.
Some projectors project an image in two different directions. For example, a projector disclosed in Japanese Patent Laying-Open No. 2005-038422 displays a virtual keyboard image on a first plane and displays a user output display image on a second plane. The lower part of the virtual keyboard image is superimposed on a keystroke detection system.
A data input device disclosed in Japanese Patent Laying-Open No. 2000-305706 detects an obstruction temporarily appearing in an input area at the outer side of the device body and determines a data entry. This data input device uses a laser diode and a diffraction optics to project an image of a virtual keyboard on the input area. The data input device uses infrared transmitter and receiver to detect a pointer or a finger on a virtual keyboard.
Portable information equipment disclosed in Japanese Patent Laying-Open No. 2006-295779 includes a first enclosure and a second enclosure connected to the first enclosure so as to be able to be opened and closed. The first enclosure has a projection-type input-displaying device showing a virtual keyboard in an input-displaying area, a projection-type display-displaying device showing character data or image data in a display-displaying area, and an input determination device detecting an obstruction appearing in the input-displaying area. The open/closed angle between the first enclosure and the second enclosure can be changed. The portable information equipment can set the input-displaying area and the display-displaying area at various positions by changing the open/closed angle.
A projector device disclosed in Japanese Patent Laying-Open No. 2007-108570 projects part of light projected from the projector device onto a sub-screen in the vicinity of the projector device. The sub-screen includes a screen and a touch panel superimposed on the screen. The projector device transmits a user operation on the sub-screen to a PC (Personal Computer) or the like.
Meanwhile, some projectors make it easier for the users of the projectors to point to points on projected images. A projector disclosed in Japanese Patent Laying-Open No. 2004-118807 includes a camera picking up an image of a screen. When the user points to a point on the screen by a laser pointer, the projector obtains the position pointed to by the pointer, based on the image by the camera. The projector re-projects a distinguishable mark on the position of the pointer.
Japanese Patent Laying-Open No. 2008-250482 discloses a mouse operation replacement system including a projector and an image pickup device capable of picking up an image of a finger that points to a part of a projected image by the projector. The projector sets a prescribed region including the part of the hand image picked up by the image pickup device, at proper brightness.
A presentation system disclosed in Japanese Patent Laying-Open No. 11-345087 includes a projector, a CCD (Charge Coupled Device) camera, and a processing unit. The CCD camera picks up an image of a display region of the image by the projector. The processing unit detects a pointing position from the shade or the real image of an object (for example, a pointer) included in the display region.